Conventional printing techniques provide for the efficient high speed printing of packaging, labels, and the like used in, for example, consumer products and other types of goods. Production runs of millions of units are not uncommon. Generally described, conventional printing techniques such as a rotogravure process involve mechanically engraving a print roller with the desired image and then applying the print roller to a substrate. Such mechanical printing techniques provide high quality graphics and colors.
The use of digital printing techniques allows for a great variety in the production of the packaging and other types of printing because digital printing does not require the engraved print roller. Although digital printing is not as fast as conventional printing, digital printing allows for “on the fly” variations in production on any scale without requiring changes to the print rollers or other types of mechanical devices. Digital printing techniques thus may allow for inexpensive variations in packaging on, for example, a regional basis, an affiliation basis, a personal basis, or on any basis whatsoever.
There is a desire to combine the high speed capability of conventional mechanical printing techniques with the easy variations offered with digital printing techniques. Combining such techniques on a high speed basis, however, has proven to be somewhat difficult in that the respective print fields must be kept in orientation for an acceptable final product. In other words, the substrate must be carefully oriented after a conventional print run and before a digital “overprint” print run to ensure that the digital overprint is properly aligned.
There is thus a desire for systems and methods for monitoring proper overprint orientation. Specifically, the orientation of a digitally printed field with respect to a conventional mechanically printed field should be monitored during high speed production on any kind of substrate.